Campers, backpackers, bicyclists and other outdoor activity enthusiasts often desire to bring with them a sleeping pad on which their sleeping bag or other sleeping accommodation may be placed in order to minimize discomfort from variations in the ground under the sleeping area and also to help insulate them from any cold or moisture in the ground. In order to achieve this goal, sleeping pads have to be made with enough thickness or bulk to satisfy these requirements. The more bulk or thickness, the heavier the sleeping pad. Often time weight is crucial to those undertaking these outdoor activities since everything they need must be carried on their back.
Air-filled outdoor products such as air mattresses are well known. Unfortunately, the thin urethane coated or laminated material used to manufacture these products often allows heat (or cold) and moisture to seep through the air mattress. Accordingly, it is more desirable to have interior layers such as heat reflective aluminum; insulated layers such as foam, felt, padding or the like on the interior of the air mattress. Manufacturing such air mattresses require that the top and bottom layers be fixed parallel to one another utilizing a connecting element or baffle, otherwise the air mattress will bow or expand like a balloon.
Although some prior art methods are used to keep the top and bottom layers of the air mattress in a fixed, parallel relationship by use of an internal air mattress structure, it has not been possible in the past to use high volume, high speed, low cost manufacturing methods such as heat welding and the like to attach the air mattress internal structure to the top and bottom layers if other internal layers of aluminum, foam or the like are present, since utilizing these attachment techniques require that the internal structure be in direct contact with the top or bottom layer sometimes with an additional TPU layer in place (adding cost and most importantly weight) or that a significant amount of heat and/or power be used to create a heat bond through such internal layers.
Accordingly, what is needed is a warm yet lightweight sleeping pad which achieves these goals as well as a method to manufacture an air filled structure that allows for ease of manufacturing.